The act of explanation in a classroom context, with particular reference to the teaching of science
The thesis is concerned with the act of explanation in classroom contexts, with emphasis upon secondary teaching particularly in science. Over one hundred explanations in eight subjects (Mathematics, Physics, Chemistry, Biology, English, History, Geography, Foreign Languages) are analysed and some fifty teachers, teaching more than one thousand pupils, are involved in studies which are cross-sectional, analytic and descriptive, utilising four instruments, namely, rating sheets, experiments, typologies and models to investigate the concerns of ten hypotheses. The rating sheets used with teachers and pupils in relation to Hypotheses H1 and H2 reveal explaining as the most central and important activity of teaching and learning, especially in science. Typologies employed for Hypotheses H4, H5 and H7 reveal respectively: relationships between question type, concept type, communicated meaning and subject origin of an explanation, understanding by pupils of their teacher's explanation shows wide variety and ranges from satisfactory to fragmentary. Experiments conducted in relation to Hypotheses H6 and H8 give results that show respectively: the gap between intended meaning and received meaning to be wider than teachers realise, unfamiliar, non-technical terms block pupil understanding. Models used in analysis for Hypotheses H3, H9 and H10 reveal respectively; two-thirds of explanations given by teachers meet philosophical conditions for deeming them to be such, contextual features influence the success of an act of explanation, conceptual features influence the success of an act of explanation, and unfamiliar non-technical words as blocking pupil understanding.